Your question suggests there are camping spots ON THE TRAILS. There aren't - the trails are narrow single track MTB trails only. As the coordinates for the listing show (and the two people who have responded so far have correctly stated) camping is only at the trailhead. There is a motorbike area as well not too far away.

https://maps.app.goo.gl/K5p14BH68omdj7HFA

I camped at the trailhead on the left — there’s a large circle of grassy area where you can park and set up camp. If you search ‘Bethel Bike Trails’ on Google maps you can find it. 21097, 21147 MS-15, Saucier, MS 39574